This invention relates to intravenous feed devices, and more particularly to a controller device for controlling the drip rate of intravenous fluid from a gravity feed container.
IV controllers rely on precise regulation of the tubing cross-sectional area for maintaining accurate flow rates. The flow rate is decreased by decreasing the area of the tubing by exerting a pressure on its walls. Control, however, is complicated by the "plastic" properties of the standard IV tubing set as a constant force on the wall of the tubing will cause the tubing to assume a new shape. This can result in cessation of the flow in as little as fifteen minutes. It is therefore further desirable to provide an IV controller which eliminates the problems of "plastic flow" of the tubing under constant force.
Prior art devices have been successfully developed for sensing the drip rate of intravenous fluid from gravity feed containers. In most applications, the controller devices require constant impaction of the tubing. The constant compaction of the tubing by continuous mechanical compression can lead to fatigue problems with the tubing. It is therefore desirable to provide a controller device which can continuously monitor the drip rate of the intravenous fluid, but also to provide a controller device that does not require constant compaction to the tubing.
Calibrating and aligning the controllers during assembly is critical in many prior art controllers. This can lead to costly calibrating procedures during assembling and manufacturing the controllers. It has also been found desirable to provide a drip rate controller which requires no calibration during assembly.
As the controllers will need to be readily portable between hospital or sick rooms, it is desirable to provide a controller assembly which is low-powered and lightweight.
Previous IV controllers had the limitation that they could only operate with either a single type or a limited number of IV tubing. It is desirable therefore to provide an IV controller which can be adapted and used with a wide selection of IV tubings.
It is another general object of this invention to provide an IV controller which is easily and economically manufactured and requires a limited number of working parts.
The present invention is directed toward solving these problems and provides a workable and economical solution to them.